Along with a reduction in line width in the semiconductor production process, the integration degree of LSI's is improving and a plurality of systems can be integrated over one chip. However, this reduction in line width increases power. This power increase is due to the scaling down of power voltage and an increase in leakage current. How to avoid thermorunnaway caused by a power increase is important for an LSI to be incorporated.
As means of avoiding the thermorunnaway caused by a power increase, it is conceivable that thermal sensors are integrated in an LSI and power is controlled based on the values of the thermal sensors.
Patent Document 1 discloses a technology for suspending the operation of a processor for a certain period of time when the temperature of the processor exceeds a certain point. Patent Document 2 discloses a technology for shifting processing to another processor when the operation temperature of one of processors contained in an LSI exceeds a certain point.    [Patent document 1] Japanese Laid-open Patent Application No. 2006-146605    [Patent document 2] Japanese Laid-open Patent Application No. 2006-018758